Multiple carburetor charge forming device



Sept. 29, 1931. H. w. ASIRE 1,825,381

MULTIPLE CARBURE TOR CHARGE FORMING DEVICE Filed Aug. 29, 1925 3Sheets-Sheet l Sept. 29, 1931.

H. w. ASIRE 1,825,381

MULTIPLE CARBURETOR CHARGE FORMING D EVICE I Fil 1925 3 Sheets-Sheet 2F? 1 i 83 1 f g Z Q78 '87 a4; I a as Sept. 29, 1931. w, AslRE 1,825,381

MULTIPLE CARBURETOR CHARGE FORMING DEVICE Filed Aug. 29, '1925 3Sheets-Sheet 3 primazy air ai Fig.1 is a 7 Patented 29, 1931 QUNITEDSTATES PATENT OFFICE gnome]: w.

ASIDE, or narrow, omo, assmnon zro emrnm norons nnsmnon conrom'rron, orDAYTON, onro, aconromrron or nmwm I I alumnus omnuamoacnanen resumennv'rcn Application Med Aug: 29; ms. Serial no. saass.

"This invention relates to charge forming devices for multicylinderinternal combustlon engines.

It isone of the objects of the present in- I 'vention'to secure moreeven distribution of fuel charge to the various engine cylinders, inorder that the engine. may start more readilyand operate moreeificiently. In the pres:

ent invention this, object is accomplished a by providing a unitarystructure adapted to be attached to the intake ports of the engine andcomprising a plurality of carburetors, each directly communicating withan engine intake port, said structurehaving a common air inlet for allof the carburetors and a single. operating member for controlling all ofthe throttle valves of the carburetors.

Further objects and advantages of the present invention will be a parentfrom the folgd' lowing description, re erence being had to theaccompanying drawings, wherein a preferred form of embodiment of thepresent invention is clearly shown.

In the drawings:

lan view of th form of the present inventlon shown attached to aninternal combustion engine which is partly in plan and partly insection; I 1

Fig. 2 is a side elevation of the apparatus at shown in Fig. 1; l

Figs. 3 and 4 are sectional views taken respectivelyon lines 33 and 4-4of Fig. 1, these viewsbeing on a larger scale than Figs.

Y 1 and .2.v

35' Fig. 5 is a modified form of primary carbureting device which may besubstituted for the form shown in Fig. 3.

The drawings indicate an internal combustion engine having a pluralityof cylinders 4.3 20, each provided with an inlet valve 21 and an exhaustvalve 22. Each exhaust valve communicates with an exhaust outlet pipe 23and each pair of intake valves 21 is served by a common intake pipe 24.

V The unitary charge forming device which is adapted to be attached byscrews 25 to the intakes 24, comprises an air manifold which providesair passage having a common inlet 31 (see Fig. 4), and branches 32, eachcommunicating with an engine intake port 24 and each provided adjacentthe intake with a,

'Venturi member 33, which is retained by a screw 34 and lock nut 35.Each branch 32 of the air manifold 30 has a constant level fuelreservoir 36 locateddirectly above the Venturi member 33. A fuel duct37, preferably castintegral with manifold 30, communicates with all ofthe reservoirs 36, having one end attached by a coupling 38 with a fuelsupply pipe 39. The fuel reservoir 36 includes a wall which is common toa portion of the duct 37 and this wall is provided with a hole 40leading into a recess 41, which is threaded to receive a valve seatmember 42 having an opening 43 adapted to be closed by a valve 44. Valve44 is carried by a lever 45 secured to a float 46 and supported by apivot pin 47 supported by a reservoir cover late 48 retained in positionby screws 49. each float bowl 36 a duct 50 extends above the normallevel of fuel and is in communication with a hole 51 in the throat ofthe Venturi member 33. Cover '48 provides a duct 52. for connecting theduct 50 with outside atmosphere. A fuel pipe 55 having at its lower enda fuel-metering orifice 54 communicates'with the passage 52 and isthreadedly attached to the cover 48. The flow of air into the passage 52is limited by an air-flow metering plug 56. When the cover 48 isassembled upon the float bowl 36 the throat of venturi ithin 33 isplaced in communication with outside Referring to Fig. 4, the common airinlet 31 is controlled by an automatic valve mechanism which comprises avalve frame 70 having an air inlet 71 and an outlet 72 commu-- nicatingwith the common air inlet 31. Adjacent the outlet 7 2 the frame 70 isprovided with a valve seat 7 3. which can'be closed by a valve 74attached to a stem 75 having its upper end connected to a dash potpiston 7 6.

Piston 7 6 slides within a cylinder 7? which is contained within acylindrical recess 78 by a spring clip 7 9 which is attached to theframe 70 by a screw 80 and spaced from the frame 70 by a s acing tube81. A coil spring 82 interposed between a s ring seat cup 83 and thehead of the piston 6 tends to retain the valve 74 upon its seat 73. Thevalve 74 is opened automatically by the suction of the engine againstthe urge of the spring 82.

The dash pot piston 76 prevents fluttering of valve 74 and stabilizesits position according to engine speed and throttle position. The piston76 is provided with a central aperture 76"which permits the escape ofair downwardly therethrough during upward travel of the piston. Howeverduring the downward travel of the piston, the aperture 76' is closed bythe check valve 76", as will be clear from viewing Fig. Therefore. theeffect of the clash pot will beto damp the opening movement of air valve74 to a much greater degree than the closing movement thereof. Thus whenthe throttle ,valves 60 are suddenly closed to idling position the airvalve 7 4 is permitted to close quickly enough to maintain sufiicientdepression in the air manifold to cause the proper rich fuel mixture tobe drawn through the duct 50.

The automatic operation of the main air valve 74 is modified by amanually actuated lever 84 attached to a shaft 85, which extends acrossthe valve frame 70 and carries within said frame a lever 86 having aforked end envary the position of the sleeve 88 and seat cup 83 in orderto var the compression in the spring 82 and there y vary the degree ofopemng of air valve 7 4 for a iven depressionin the air manifold 30. yincreasing the compression of-spri-n 82 less air is admitted throughvalve 74 for a given depress sion in the air manifold 30 and hence aricher fuel mixture is drawn into the engine whenever desired. Thesuction of the engine causes rimary air to enter the plug 56 and liquidel to flow upwardly through the duct 55 and form an overrich mixture ofair and fuel in duct 50 which is drawn into the venturi 33 and mixeswith the flow of air through the branch 32. The float 46 operates in theusual manner to close the fuel inlet passage'43 and maintain the levelof fuel in the bowl 36 substantially constant.

Fig. 5 illustrates a modified form of primary carburetin device whichmay be used with the air manifold 30 in place of the form shown in Fig.3. In Fig. 5 the cover plate 900i the float bowl 36 has a fuel well 91and a fuel mixture duct 92 which registers with the duct 50 extendingupwardly through the float bowl 36. Atmospheric air enters therestricted air inlet tube 93 which extends downwardly within the duct 92leaving an annular has an annular groove 102 which registers with theduct 50. A series of holes 103 form a communication between the upperportion of the groove 102 and the throat of the venturi 101. The lowerhalf of the groove 102 forms a semi-annular well 104 which communicateswith the center of tile .Venturi throat through the stand pipe 105.

The operation of the device ofFig. 5 is as follows: I

At slow engine speeds, say that corresponding to a car speed of'15 milesper hour, the depression in the air manifold '30 will create adepression in duct 92 which in turn will cause air to enter the primaryair inlettube 93 and liquid fuel to be drawn up through pipe 97, outthrough low speed fuel orifice 99 into the well 91, and thence throughthe low speed fuel jet 95 forming a rich mixture of air and fuel in duct50. This rich mixture is drawn through the holes 103 and there sprayedinto the air passing through the venturi 101 to form a mixture of theproper proportions for the engine when running at the slower speeds. Ifnow the throttle 60 be opened to cause the engine speed to materiallyincrease, the increased depression in air manifold 30 and the increasedair flow through the venturi 101 will greatly increase the de ression induct 92 which in turn will cause uel to be drawn up into well 91 throughboth orifices 99 and 100 faster than it can flow out through the jet 95and hence the fuel level in well 91 will rise until it also flowsthrough the larger high speed jet 96. The combined fuel flow throughboth jets 95 and 96 is such as to maintain the proper. fuel and airratio to the engine at the higher speeds thereof.

Now if the throttles 60 be closed to materially reduce the engine speedwhile the fuel well 91 is full, the air flow through venturi 101 andrimary air inlet 93 will be greatly reduced But the greater part of thefuel in well 91 will run out through a jet 95 by gravity and flow downthrough ducts 92 and 50 and fill the semi-annular well 104 since therewill not be suflicient suction to cause this superfluous liquid fuel toenter holes 103 mixture passing to theengme for a few moments to give aquick acceleration to the englue. The well 104 therefore serves as anaccelerating well and is filled by the dumping of well 91 each time theengine speed is materially reduced by closing the throttles.

Thus the well 104 is always ready to deliver 1 an accelerating richmixture when the throt- .opened to admit air according tles are suddenlyopened.

An important feature of this primary carburetor- IS the extension of theprimary air inlet tube 93 beyond both the fuel jets 95 and 96. Anyvariation in the flow of fuel through these jets due to turbulenteffects in the air stream is thus avoided and hence more accurate anduniform metering of the liquid fuel obtained.

One of the important advantages of the present invention is that of moreevenly distributing fuel charge to the various cylin-- ders. Each engineintake port is provided with a carburetmg .device which is situatedrelatively close to the calinder intake valves. Since there is very lite chance of uneven distribution occurrin between a pair of intakevalves, it is evi ent that the distribution will be more uniform than inthe case where a single carburetor is used to supply fuel charge to fouror more cylinders.

Another advantage lies in the simplicity of structure, enabling thedevice to be assembled on an engine in a simple manner, and

to be connected with the fuel line by only one pi e connection.

Vhile the forms of embodiment of the present invention as hereindisclosed, constitute referred forms, it is to be understood that ot er'forms 'might be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. In a charge forming device for a multicylinder internal combustionengine having a plurality of intake ports, an air manifold having abranch leading to each engine intake port and a common main air inlet, aspring closed valve in said main air inlet which is to the depression insaid manifold, an in ividual'carburotor for supplying fuel to each ofsaid branches relatively close to said engine intake ports, a throttlevalve in each branch on the engine side of the point of fuel admission,common means for concurrently actuating all of said throttle valves, andmanual means whereby the operator may at will ch the spring tension onsaid spring close valve to vary the amount of air admit- 9 ted to saidmanifold and hence equally vary the fuel and air ratio drawn into eachof said engine intake ports.

2. In a charge forming device for a multicylinder internal combustionengine having a plurality of spaced intake ports, an airmanifold havinga'branch leading to each engine I which is opened to admit air accordingto the a depression in said manifold, an individual prlmary carburetorassociated with each manifold branch, said carburetor being locatedclosely adjacent tothe engine intake port, and adapted to supply anoverrich mixture of fuel and air to its associated manifold branch closeto said port, a throttle valve in each manifold branch for controllingthe flow therethrough, and common actuating means for said throttles.

3. In a charge forming device for a multicylinder internal combustionengine having a plurality of spaced intake ports, an air manifold havinga branch leading to each engine intake port and a common main air inlet,a spring closed valve in said main air inlet which is opened to admitair according to the depression in said manifold, a plurality ofindividual carburetors, one for each branchvof the manifold and each ofwhich is provided with a constant lever fuel chamber, said carburetorsbeing located closely adjacent the engine intake ports and adapted tosupply a mixture of fuel and air to the manifold branches close to saidports, a throttle valve in each manifold branch for controlling the flowtherethrough and common actuating means for said throttles.

4. In a charge forming device for a multicylinder internal combustionengine having a plurality of spaced intake ports, an air manifold havinga branch leading to each engine intake port and a common'main air inlet,a spring closed valve in said main air inlet which is opened to admitair according to the depression in said manifold, a plurality ofindividual carburetors, each of which is provided with a constant levelfuel chamber, said carburetors being sup orted by the manifold branchesclosely adjacent the engine intake ports and adapted to supply fuel tosaid branches close to said ports,

a plurality of spaced intake ports, an air manifold having a branchleading to each engine intake port and a common main air inlet, a springclosed valve in said main air .inlet which is opened to admit airaccording to the depression in said manifold, a

plurality of individual carburetors, each of which is provided with aconstant level fuel chamber, said carburetors being cast integral withthe manifold branches closely adjacent the engine intake ports andadapted to supply fuel to said branches close to said ports, a throttlevalve in each manifold branch 4 mama for controlling the flow therethrouh, and common actuatin means for said v ves.

6. In a charge orming device for a multicylinder internal combustionengine having a plurality of intake orts, an air manifold having abranch leading to each engine in take port and a common main air inlet,an automatically closed valve in said main air inlet which is opened toadmit air according to the depression in said manifold, an individualprimary carburetor supported by each manifold branch and adapted tosupply an overrich mixture of fuel and air to each manifold branch, theamount of mixture su plied to each branch being up roximatey directly inaccordance with the epression 1n said branches, a throttle valve in eachmanifold branch and common actuating means for said throttles.

7 In a charge forming device for a multicylinder internal combustionengine having a plurality of intake ports, an air manifold having abranch leading to each engine intake port and a common main air inlet,an automatically closed valve in said main air inlet which is opened toadmit air according to the depression in said manifold, an individualprimary carburetor supported by each manifold branch adjacent the engineintake port and adapted to supply an overrich mixture of fuel and air toeach manifold branch close to said port, the amount of mixture suppliedto each branch bein a proximately directly in accordance with thedepression in said branches a throttle valve in each manifold branch andcommon actuating means for said throttles.

In testimony whereof I hereto afiix my signature.

HORACE W. ASIBE.

